This bird's nest fungus is widely distributed in North America, but seldom collected. It grows on deadwood (including driftwood in coastal areas), and until maturity appears more like a puffball or slime mold than a bird's nest fungus, since it belongs to a fairly small group of bird's nest fungi that do not form goblet-shaped splash cups to hold the spore-filled "eggs." Instead, the outer surface breaks up irregularly, leaving an exposed pile of eggs. Within this group of bird's nests, Nidularia pulvinata is distinguished by its brownish outer surface, its grayish brown eggs, and microscopic features.

Description:

Ecology: Saprobic; growing scattered or gregariously on old deadwood (including driftwood); usually growing on the upper sides of logs; summer and fall; widely distributed in North America.

Nest: To about 1 cm across; shaped like a glob or a ball; outer surface at first shaggy, powdery, or velvety, becoming smoother with age (but often appearing "lumpy" as a result of being pressed against the eggs inside); brownish or grayish brown, fading to nearly whitish; at maturity breaking up irregularly to expose a pile of eggs.